1. Technical Field
The present invention relates to a filter device and to a liquid droplet ejecting device. More specifically, the present invention relates to a filter device that removes wastes and foreign substances from inside a liquid, and to a liquid droplet ejecting device that ejects the liquid, which is passed through the filter device and is supplied thereto, from the nozzles of a liquid droplet ejecting head.
2. Related Art
A filter is provided in an inkjet recording device that ejects ink droplets from the nozzles of an inkjet recording head and prints on a recording medium. This filter is provided in the ink supply path of the inkjet recording head in order to prevent clogging of the nozzles or deterioration of the ink ejecting capabilities, due to wastes and/or foreign substances found in the ink.
With recent inkjet recording heads, there is a trend towards an increase in the number of nozzles provided in one recording head, or an increase of repeat-frequency of ejecting of ink, for the purpose of high-speed printing. Also, progress is being made in making the nozzle cross-sectional area smaller in order to make the ejected ink droplets smaller, for the purpose of achieving high-quality printing.
Due to these developments, certain qualities are demanded of the above-mentioned filter, namely, the filter needs to be able to remove even smaller wastes and foreign substances, and it must have a form with which loss of pressure is small. For this reason, progress is being made in the miniaturization of the filter meshes and the increasing of the area of the filter. However, when the filter area is made larger, the size of the inkjet recording head is increased depending on the arrangement of the filter. As a way of improving on this, increases in size of the inkjet recording head can be suppressed by dividing a filter into plural filter portions and being arranged in parallel.
Nonetheless, with the above-described configuration, the channel at the downstream side of the filter branches into plural channels so when bubbles generated in the ink stop in one channel, ink flows in the other channels so sufficient external force cannot be applied to the bubbles. There is a problem in that the ability to remove bubbles (i.e., discharge them) from the channel where the bubbles stop worsens and this tends to cause deterioration of the ink ejecting capability.